John d



JoHN D. cRocKnR, or NoRW1cH`,Y-coNNncT1cUr.

Letters Patent No. 106,332, dated August 16, 1870.

STRETCHER FOR 'PICTURE-FRAMES,

The Schedule referred to in these Letters Patent and making part of the same To all whom it may concern:

Be it known that I, JOHN D. Onocxnn, of Nor wich, in the county-ot' New London and State of Connecticut, have invented an Automatic Metallic Stretcher for Picture-Frames; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to t-he accompanying drawing making part ot' this specification, in which- Figure l is a view of the back side of one corner of a pictnrefraine, Vhaving my automatic stretcher applied to it.

' Figure 2 is a sectional view of tig. 1, showing the manner of applying the springs to act upon the'trame pieces.

Figure 3 is'an edge view ot' the stretcher, applied to one of the framepieces.

Figure t is a perspective view of the stretcherplate.

Similar letters of reference indicate corresponding parts in the several figures.

The object of this invention is to keep the canvas attached to picture-frames and other frames nnderconstant and proper tension, bythe employment of rightangnlar or knee-plates and springs applied to the angles of the frames, in such manner that the springs ot each plate will act constantly in the direction ot` the length of their respective trame-pieces, to keep the canvas tight and smooth; at the same time the plates themselvesnilloperate as braces and supports for the frame at its angles, to prevent it from twisting, as will be hereinafter explained. l f

'Io enable others skilled in the art to understand my invention, I will explain its construction and operation.

In theaccompanying drawing, figs. l and 2, I have represented my invention applied to the mitered angle ot' two lpicces, A A, of a frame adapted to have canvas applied to it. i

The device consists of three pieces, to wit., a rightangular plate, and two springs.

Ihe plate B, which may be made of brass, cast-iron, or other suitable metal, has formed, on its front side, two ribs, G C, at right angles to cach other, and terminating outwardly in circular heads, c e.

lhe ribs are `made 'seitlich-cular, and are hollowed, so as to aord strength, and atthe same time lightness. They serve as guides and braces when applied into holes, g g, made longitudinally into the ends ofthe frame-pieces A A, and prevent lateral displacement and twisting of these pieces. Theyoperate as tenons' in the mort-ises g g, but are notiit-ted very tight into these mortises. t

The circular heads c e, at the extremities of the ribs, serve, when the device is applied to a frame, as

external abntments for two springs, S S, which are compressed in the holes or mortises inv such manuel' as to operate by their recoil to force the trame-pieces apart.

It will be seen that the springs operateI at right angles to one another, and thus would stretch canvas applied to the frame in two directions.

'lhe narrow portions, r, which connect the ribs C C to the plate B, are received into slots made through the back parts ot' the frame, and which communicate with the mortises g g.

' The external plate B lies snugly against the back side of the frame pieces, stiifcns the ribs C U, prevents lateral displacement of the frame pieces at the joints or corners, and also serves, by means of the perforations a a, through which nails are driven into the frame before the canvas is` applied to it, as a means for holding the frame pieces tightly together, and keeping the springs compressed while stretching the canvas, and fastening it ou the frame, after which the nails are withdrawn, and the 'springs allowed to op crate to keep the canvas tightly stretched.

I am aware that springs have been employed before my invention, with the object of keeping tight the canvas on the frame; but I am not aware that springs have ever been so employed for this purpose that they would, by their recoil, operate to force the trame-pieces apart in a direction at right angles to` 'their respective frame-pieces.

a right-angular tenon, adapted to be Vreceived in mortises in the frame to pieces tostiiiln the joint of a frame, substantially as above described, has ever been known or used before myinvention thereof; therefore, while I do not claim springs applied to stretchcrs in the manner shown in the patent granted to Joel E. Todd, September 1S, 1866,

What I do claim as new, and Letters Iatent, -is- A right-angular tenon or rib, applied onone side of a plate, B, and adapted to operate in conjunction with springs S S, applied in mortises in a frame, substantially as described.

Vitnesses:

J. V. CAMPBELL, EDM. F. Bnowx.

desire to secure. by

JOHN D. cRocKEa.

Nor am I aware that 

